<html>
<head>
    <meta http-equiv="Content-Type" content="text/html;  charset=gb2312">
    <meta name="GENERATOR" content="Microsoft  FrontPage  4.0">
    <meta name="ProgId" content="FrontPage.Editor.Document">
    <style> .a3 {
        width: 30;
        border: 0;
        text-align: center
    } </style>
    <script> function mask(obj) {
        obj.value = obj.value.replace(/[^\d]/g, '')
        key1 = event.keyCode
        if (key1 == 37 || key1 == 39) {
            obj.blur();
            nextip = parseInt(obj.name.substr(2, 1))
            nextip = key1 == 37 ? nextip - 1 : nextip + 1;
            nextip = nextip >= 5 ? 1 : nextip
            nextip = nextip <= 0 ? 4 : nextip
            eval("ip" + nextip + ".focus()")
        }
        if (obj.value.length >= 3) if (parseInt(obj.value) >= 256 || parseInt(obj.value) <= 0) {
            alert(parseInt(obj.value) + "IP地址错误！")
            obj.value = ""
            obj.focus()
            return false;
        } else {
            obj.blur();
            nextip = parseInt(obj.name.substr(2, 1)) + 1
            nextip = nextip >= 5 ? 1 : nextip
            nextip = nextip <= 0 ? 4 : nextip
            eval("ip" + nextip + ".focus()")
        }
    }

    function mask_c(obj) {
        clipboardData.setData('text', clipboardData.getData('text').replace(/[^\d]/g, ''))
    } </script>
    <title>IP地址输入</title></head>
<body>IP地址输入
<div style="border-width:1;border-color:balck;border-style:solid;width:165;font-size:9pt">
    <input type=text name=ip1
                                                                                                 maxlength=3 class=a3
                                                                                                 onkeyup="mask(this)"
                                                                                                 onbeforepaste=mask_c()>.
    <input type=text name=ip2 maxlength=3 class=a3 onkeyup="mask(this)" onbeforepaste=mask_c()>.
    <input type=text
                                                                                                        name=ip3
                                                                                                        maxlength=3
                                                                                                        class=a3
                                                                                                        onkeyup="mask(this)"
                                                                                                        onbeforepaste=mask_c()>.
    <input type=text name=ip4 maxlength=3 class=a3 onkeyup="mask(this)" onbeforepaste=mask_c()></div>
</body>
</html>